What's in My Water?

Your Drinking Water

Milky, Cloudy or White Water

Cloudy water is usually caused by tiny air bubbles in the water similar to gas bubbles in carbonated drinks. This usually happens during winter months when air gets mixed into the cold water and then the water is warmed as it sits in household plumbing or hot water heaters. Cold water can hold more air than warm water. When the warmed water is released from a faucet into a glass, the air bubbles rise to the top and the water clears. There is no health risk associated with air in water.

Air can also occur in water after routine repairs to waterlines. If the air does not clear up or if it seems excessive, contact your Water Resources Department.

Chlorine Taste and Odor

We are required by law to provide disinfectant (chlorine) residuals to the taps of our customers to protect the water from harmful bacteria. This may mean that you encounter chlorine-type tastes and odors from time to time. If you find these objectionable, fill a container with water and store it in the refrigerator for drinking. Leave the cap slightly loose and most of the chlorine smell should dissipate.

You can also use a hand-held pitcher with an activated carbon filter to remove chlorine, or install a point-of-use water treatment device on a faucet for your cooking and drinking water. Be certain that the device has been tested by an independent organization for aesthetic (non-health) use. ANSI/NSF Standard 42 establishes minimum requirements for materials, design and construction, and performance of drinking water devices that reduce specific aesthetic-related contaminants in public or private water supplies. These products usually contain activated carbon that can remove many chemicals that affect taste and odor, including chlorine.

Point of use devices contain filter cartridges that must be changed out periodically. Be sure to follow manufacturer’s recommendations to replace the cartridges. If you plan to store water from these devices, treat the water as a food product, and use clean, airtight containers and refrigerate, as the water is no longer protected from bacteriological contamination.

Discolored Water

Yellow, rusty, or brownish colored water is usually due to flow changes in the system that stir up iron and manganese-containing sediments. There are no health-related limits for iron or manganese in drinking water. These minerals, however, can result in staining of white laundry. Items stained by washing in discolored water should not be bleached (this will set the color into the fabric). They should be washed again in clear water. Using a laundry cleaner specifically manufactured for iron removal may be helpful as well. These products are available at most laundry product retailers.

Discolored water can also be the result of in-house plumbing problems, such as the attachment of dissimilar metals like copper and galvanized pipes, or to cracked glass liners in hot water tanks. In general, these in-house discolored water problems will be characterized by a spurt of discolored water when the water is first turned on or will be limited to the hot water.

Rusty water can also occur in the system if there is a change or increase in water flow caused by water main breaks, valve operation, or fire hydrant activation. These activities dislodge small particles of rust and stir up sediments in pipes. It is a temporary condition and should clear up in a couple of hours. The Water Resources Department should be aware of what is happening at any particular time and how long the condition should last. If possible, avoid dishwashing or laundry until the condition clears up.

If you experience ongoing discolored water for which you can find no in-house remedy, call your Water Resources Department.

Musty, moldy, or earthy taste or odor in the water

Earthy/musty tastes and odors that occur in drinking water can be related to several factors. These taste and odor causing substances can be very difficult to detect at the treatment facility. There are two common causes of a musty, moldy, or earthy taste or odor in the water: bacteria growing in your drain, or certain types of organisms growing in the City's water supply.

By far, the most common cause of this type of problem is the drain. Over time organic matter (such as hair, soap, and food waste) can accumulate on the walls of the drain. Bacteria can grow on these organic deposits. As the bacteria grow and multiply, they produce gases that can smell musty or moldy. These gases accumulate in the drain until the water is turned on. As the water runs down the drain, the gases are expelled into the air around the sink. It is natural to assume the bad odor is coming from the water because the smell is noticeable only when the water is on. However there is nothing wrong with the water, but the drain may need to be disinfected.

The other cause of this type of taste or odor in the water is much less common and results from certain types of algae, fungi, and bacteria growing in the water supply reservoirs. As these organisms grow and multiply, they excrete small amounts of harmless chemicals into the water that cause a musty, moldy, or earthy taste and odor. The two most common chemicals are geosmin and methylisoborneal (MIB). Although these chemicals are harmless, the human senses of taste and smell are extremely sensitive to them and can detect them in the water at concentrations as low as 5 parts per trillion (nanograms per liter).

Similar “stale” tastes and odors may also occur in distribution lines related to low flow situations. The remedy in this case usually involves flushing out of the affected lines by City crews. Also, anytime plumbing has been unused for a long time, the water can develop an unpleasant taste, so faucets should be run a short time to bring in fresh water. There are no adverse health effects associated with earthy/musty taste and odor substances.

Fluoride

Most Water Resources departments fluoridate the water in all of its treatment facilities. Fluoride is provided at a level of about 1 milligram per liter which provides an optimal level of fluoride for protection against tooth decay.

Pink or black residues on surfaces in contact with water

Such residues may occur in showers, toilet bowls or tanks, pet bowls, bath tub toys, coffee reservoirs, cold air humidifiers—on any surface that stays moist and is not cleaned thoroughly and regularly. These are generally the result of biological growth—molds, fungus, bacteria or algae that have originated from the air or the surfaces themselves. These microbes grow well in moist areas and the water that remains in these areas has typically lost its chlorine (disinfectant) through natural reaction or volatilization. The simple remedy is to keep such areas dry and to clean them regularly with a disinfectant solution.

White or black particles

These can occur as a result of degradation of hot water tank dip tubes (white) or degradation of faucet gaskets, supply tubing or pipe coatings (black). If the particles are occurring due to these causes, some basic trouble-shooting may help isolate the problem: determine whether the problem occurs only in hot water piping or certain faucets.

My water is cloudy and/or tastes bad. Who should I contact?

Contact your Water Resources Department to report concerns about the taste, smell, or appearance of your water. Hydrant flushing may be required to clear lines of cloudy water due to construction or maintenance of water mains.

Is my water safe? Do I need to boil my water or seek an alternate source due to specialized medical needs?

Drinking water as provided by public water suppliers is clarified and disinfected. It is not sterile, however. Those with severely compromised immune systems—advanced AIDS, organ transplant patients, cancer patients on chemotherapy, or those with other conditions that greatly impair the natural immune response may wish to take special precautions regarding the water they consume, such as boiling the water prior to use. To completely eliminate the possibility of any microbial exposure from water are advised, bring water to a full rolling boil for one minute, allow it to cool, and store it in clean, refrigerated conditions. Persons with these concerns are encouraged to seek advice from their physicians.

In the event of a major interruption in water service, such as a water main break, customers may be advised to boil their water. This can happen even in properly treated public water supplies like Greensboro’s. When water service is interrupted and mains are depressurized, there is an increased risk that substances might be drawn into mains through seepage or cross-connections. As a result, in larger outages, systems are required to issue “boil water advisories” until bacteriological sampling shows that the water has not been contaminated. Such sampling usually takes 24 to 48 hours to be completed once water service is restored. The Water Resources Department's monitoring of the water in such depressurization instances has consistently shown that the water has not been contaminated.

My family has been sick. How can I be sure my water is not the cause?

With increased public awareness on issues related to health and infectious diseases, the Water Resources Department is occasionally asked whether City water could be the cause of illness. This is highly unlikely, since the City provides water that is treated to high quality standards, uses utmost care in maintaining its distribution system, and adds chlorine at booster stations where needed. In response to such inquiries, however, most Water Resources Department schedules on-site water testing for bacteria and chlorine (disinfectant) residuals, as well as other basic water quality parameters if the customer so desires.